#!/bin/bash

green='\e[32m'
defult='\e[39m'
sum=1

function fun_sum()
{
	for((i=1;i<=$1;i++))
	do
		sum=$((sum*i))
	done

}

read -p "please enter number n:" num

fun_sum $num

echo -e "\nthe result is:$green $sum"
